Traveling guide for control cable



March 3, 1970 e. R. WHITE TRAVELING GUIDE FOR CONTROL CARLE 2 Sheets-Sheet 1- Filed May 20, 1968 INVENTOR. GEROME R. WHITE ATTORNEY) March 3, 1970 G. R. WHiTE TRAVELING GUIDE FOR CONTROL CARLE 2 Sheets-Sheet 2 Filed May 20, 1968 FIG. 3

FIG.

5 INVENTOR.

GEROME R WHlTE A TTORNE YJ United States Patent US. Cl. 187-1 6 Claims ABSTRACT OF THE DISCLOSURE A traveling guide for the traveling control cable that hangs in a catenary loop from the bottom of an elevator car is disclosed. The traveling guide for the control cable comprises a carriage that is mounted on the vertical guide rails of the elevator shaft below the elevator car and that is supported by at least one carriage support cable one end of which is secured to the bottom of the elevator car and the other end of which is secured to the side of the elevator shaft. The carriage which travels vertically up and down within the elevator shaft a distance equal to the vertical travel of the catenary loop at the lower end of the control cable, is provided with guide means for the lower end of said catenary loop. The catenary loop extends through the guide means mounted on the carriage, the guide means receiving and loosely confining the lower end of the loop without subjecting the control cable to undue stresses or loads.

BACKGROUND OF THE INVENTION Building elevators, personnel and material construction hoists, and similar apparatus comprise, in their major components, an elevator shaft or tower having at least two vertical guide rails secured to the interior of the shaft, an elevator car mounted on the guide rails for vertical travel within the shaft, a stationary motor driven elevator hoist means connected to and supporting the elevator car, hoist motor control means in the car for controlling the operations of the hoist motor, and a traveling control cable connecting the control means in the elevator car to the stationary hoist motor. One end of the traveling control cable is normally secured to the elevator car and the other end is secured to the side of the elevator shaft, the control cable hanging freely in a catenary loop between its two points of support. Because one end of the control cable is attached to the moving elevator and the other end is attached to the stationary shaft, the catenary loop at the lower or loop end of the cable rises and descends exactly one-half the distance that the elevator car rises and descends.

The traveling control cable hanging in a long loop from the bottom of the elevator car can cause serious difliculties if the cable becomes twisted or kinked or becomes entangled with other equipment within the elevator shaft. To overcome this problem, the control cable is usually made of a special cable construction which permits the freely hanging cable to assume the desired cate nary loop without twisting or kinking. However, despite the special construction of the control cable, there remains some tendency for the cable to become twisted or entangled with other equipment within the elevator shaft, especially in outdoor installations where the elevator shaft comprises a skeletal tower open to wind and weather. Accordingly, it has heretofore been proposed that a traveling guide be provided for the lower or loop end of the control cable. Usually, the lower or loop end of the cable is confined by the traveling guide and in some cases actually supports all or a substantial part 3,498,414 Patented Mar. 3, 1970 of the weight of the guide mechanism. For example, one well-known type of traveling guide comprises a weighted sheave or pulley that rests in and is supported by the loop at the lower end of the control cable, the sheave being journaled in a suitable structure which hangs freely on the loop or which is slidably connected to one of the vertical guide rails within the elevator shaft. As a consequence, the loop at the lower end of the cable no longer has the natural catenary shape that the cable is designed to assume. In addition, the cable is required to support a load or weight it is not designed to carry.

SUMMARY OF THE INVENTION After an intensive investigation of the problems of twisting and entanglement of traveling elevator control cables, I have developed a new traveling guide for such cables which permits the lower end of the cable to hang in an essentially natural or undistorted loop while effectively preventing twisting or entanglement of the cable. The traveling guide of my invention comprises a carriage mounted for vertical travel on the vertical guide rails of the elevator shaft 'below the elevator car. At least two carriage support sheaves are rotatably mounted on the carriage adjacent the vertical guide rails, and at least one carriage support cable is reeved through the sheaves with one end of the cable secured to the elevator car and the other end secured to the elevator shaft at a point between the top and the bottom of the shaft. Control cable guide means are secured to the carriage, the guide means being adapted to receive and loosely confine the catenary loop at the lower end of the control cable without subjecting the cable to undue stress or loads. Because one end of both the control cable and the support cable are secured at a fixed point in the elevator shaft, both the catenary loop at the lower end of the control cable and the carriage of the guide move up and down within the elevator shaft at exactly the same rate. As a consequence, the catenary loop at the lower end and the cable remains within the guide means of the carriage without any essential change in their respective positions. That is to say, as the elevator car rises within the shaft, both the loop at the lower end of the control cable and the carriage of the traveling guide rise together one-half the distance traveled by the car, and when the elevator car descends within the shaft, the catenary loop of the control cable and the carriage of the traveling guide likewise descend together one-half the distance traveled by the car. Moreover, the catenary loop received in the control cable guide means is loosely confined therein without undue distortion or significant load, while at the same time undesirable twisting and entanglement of the control cable is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS The traveling guide of my invention will be better understood from the following description thereof in conjunction with the accompanying drawings of which:

FIG. 1 is a side elevation of an elevator tower provided with an advantageous embodiment of the traveling guide DETAILED DESCRIPTION The traveling guide for traveling control cables of my invention may be used in conjunction with any conventional elevator or personnel and material hoisting apparatus in which the elevator car is mounted on vertical guide rails in an elevator shaft or tower and in which the car is provided with a control for the hoist motor and with a cable that hangs freely from the bottom of the car and from a point on the side wall of the elevator shaft in the form a catenary loop. By way of example, the embodiment of my invention shown in FIG. 1 is employed in an elevator structure of the type commonly found at building construction sites, the elevator shaft comprising a skeletal steel tower made of steel frame work that may be erected to any desired height as required by circumstances.

In the elevator structure, shown in FIG. 1, the skeletal steel tower 10 is provided with at least two vertical guide rails 11 and 12 that are mounted on the interior of opposite side walls of the tower. An elevator car 14 disposed within the elevator tower 10 is mounted for vertical travel on the vertical guide rails 11 and 12. The tower 10 is provided with a cathead beam 15 mounted on the tower adjacent the upper end thereof and a cathead pulley 16 is rotatably mounted on the cathead beam 15. An elevator car support cable 17 extends from the car 14 over the pulley 16 and thence down to the windless 18 of a motor driven hoisting apparatus 19 located at the base of the tower 10. The motor 20 of the hoisting apparatus 19 is controlled by an operator riding in the elevator car 14 by means of a traveling control cable 21 which connects the car to the hoist motor. One end of the control cable 21 is secured to the bottom of the car 14 and travels up and down within the tower 10 with the car. The other end of the control cable 21 is secured to the side of the elevator tower 10 at a point 22 located between the upper and lower ends of the tower 10. As a result, the control cable 21 normally hangs in a smooth catenary shape from its two points of support, and as the car 14 travels up and down in the tower 10 the loop 23 at the lower end of the catenary also travels up and down exactly one-half the distance traveled by the car.

In accordance with my invention, the control cable 21 is provided with a traveling guide that is adapted to receive and loosely confine the loop 23 at the lower end of the catenary shape, thereby preventing the cable 21 from becoming twisted or entangled in the tower, without unduly distorting the catenary shape of the cable or imposing any significant extraneous stress or load on the cable. In the embodiment of my invention shown in FIGS. 1, 2 and 3, the traveling cable guide comprises a carriage 25 mounted for vertical travel on the guide rails 11 and 12 by means of the four sets of conventional guide rollers 26, 27, 28 and 29. A pair of carriage support sheaves 30 and 31 are rotatably mounted at opposite ends of the carriage 25 adjacent the guide rails 11 and 12. The carriage 25 is supported by one or more carriage support cables which extend from the car 14 downwardly about the sheaves 30 and 31 and then upwardly to the side wall or walls of the tower 10. In the preferred embodiment, one carriage support cable 32 extends from the bottom of the car 14 downwardly about the sheave 30 and then up to the cable anchor means 33, and a second carriage support cable 34 extends from the car 14 downwardly about the sheave 31 and then up to the cable anchor means 35, the anchor means 33and being located on the side walls of the tower between the upper and lower ends thereof. In the embodiment shown in FIG. 2, both of the carriage support sheaves 30 and 31 are located on the same side of the carriage 25, Whereas, in the modification of this embodiment shown in FIG. 3, the carriage support sheaves 30 and 31 are located on opposite sides of the carriage 25, an arrangement that improves the balance of the carriage. Alternatively, the two carriage support cables 32 and 34 are replaced by a single carriage support cable 36 (shown in outline, FIG. 2) that extends from the car 14 downwardly about both carriage support Sheaves 30 and 31 and then upwardly to the side wall of the tower 10. In both cases the arrangement of car 14, carriage 25 and support cables 32 and 34 (or the support cable 36) insures that the carriage 25 will move vertically exactly the same distance and in the same direction as the loop 23 at the lower end of the cable 21, this distance being one-half the distance traveled by the car 14.

Control cable guide means for the lower or loop end 23 of the control cable 21 are mounted on the carriage 25. In the embodiment shown in FIGS. 1, 2 and 3, the guide means comprises a pair of relatively large diameter sheaves 38 and 39, one of which is rotatably mounted in line with the downward leg 21a and the other of which is rotatably mounted in line with the upward leg 21b of the control cable 21. The cable legs 21a and 21b hang freely from their respective points of Support and are received without constraint in the grooves formed in the sheaves 38 and 39. In order to insure that the cable 21 will remain in the grooves of the cable control sheaves 38 and 39, the length of the cable 21 and/or the spacing of the sheaves 38 and 39 are advantageously adjusted so that the loop 23 will be slightly foreshortened as shown in FIG. 2, and to this extent the natural catenary shape of the loop 23 is slightly distorted. However, this slight distortion of the natural catenary shape of the loop 23 imposes no appreciable stresses or extraneous loads on the cable 21, and in no event is any appreciable portion of the weight of the carriage 25 borne by the cable 21. Vertical movement of the elevator car 14 causes the carriage 25 and the loop 23 at the lower end of the cable 21 to move vertically a proportionate amount (that is, one-half the distance traveled by the car 14). However, as the cable '21 hangs freely and without undue restraint in the grooves of the sheaves 38 and 39, this vertical movement imposes no significant stresses or extraneous loads on the cable 21 despite the fact that the cable guide means (namely, the sheaves 38 and 39 mounted on the carriage 25) effectively prevent the cable from becoming twisted about itself or entangled with other equipment in the elevator tower 10.

In the preferred embodiment of my invention shown in FIGS. 4 and 5, the control cable guide means comprises a plurality of pairs of guide rollers (41a and 41b, 42a and 42b, etc.) disposed at spaced intervals along an arcuate or curved path that essentially corresponds to and coincides with the natural catenary loop 23 at the lower end of the cable 21. The pairs of guide rollers are rotatably mounted on a suitably curved framework 50 that is, in turn, secured to the carriage 25. Moreover, the guide rollers are so configured, and/or the rollers of each pair are so spaced apart, that the loop 23 of the freely hanging cable 21 can extend between the pairs of rollers 41a, 41b, etc. disposed in the aforementioned curved path on the framework 50 without actually coming into contact with any of the rollers. Thus, as shown in FIG. 5, the guide rollers can be formed with relatively deep and wide grooves which, when paired together, define a roughly circular area several times greater in diameter than the diameter of the control cable 21. However, as will be readily understood by those skilled in the art, other forms and configurations of guide rollers, including pairs of smooth cylindrical rollers spaced an appropriate distance apart, can be employed in place of the deeply grooved pairs of rollers shown in FIG. 5.

As before, vertical movement of the elevator car 14 causes the carriage support cables 32 and 34 and sheaves 30 and 31 to move the carriage 25 vertically a distance equal to the vertical travel of the loop 23 at the lower end of the control cable 21. As noted, the loop 23 of the freely hanging cable 21 extends through the cable guide means (that is, between the pairs of guide rollers 41a and 41b, etc.) without unnecessary or undue contact with the guide rollers. As a practical matter, however, contact between the cable loop 23 and the guide rollers cannot be avoided during vertical movement of the loop 23 and the carriage 25. Therefore, in order to minimize uncontrolled play and slapping of the cable loop in the cable guide means, it is desirable that the cable 21 and/or the spacing of the uppermost guide rollers 41b and 49 beadjusted so that the downward leg 21a of the cable 21 will be in light contact with the guide roller 41b and the upward leg 21b of the cable will be in light contact with the 'guide roller 49 when the elevator 14 and carriage 25 areat rest (i.e., are motionless). Although this light contact between the cable 21 and the uppermost guide rollers 41b and 49 may slightly distort the natural catenary shape of the loop 23, in no event is the cable 21 placed under'undue stress or required to support any significant load other than the inherent weight of the freely hanging cable itself. As a result, the loop end of the cable is loosely confined and controlled, thereby preventing undesirable twisting and entanglement of the cable, without imposing undue stress or load on the cable.

I claim:

1. In the combination comprising an elevator shaft having at least two vertical guide rails secured to the interior of said shaft, an elevator car mounted for vertical travel within said elevator shaft, motor driven elevator hoist means connected to and supporting the elevator car, hoist motor control means in the elevator car, and a traveling control cable connecting the control means in the elevator car to the hoist motor, said traveling control cable being secured to the elevator car and to the elevator shaft and hanging freely in a loop therebetween,

the improvement which comprises a traveling guide for said traveling control cable, said traveling guide comprising a carriage mounted for vertical travel on said vertical guide rails below said elevator car, at least two carriage support sheaves rotatably mounted on the carriage adjacent the vertical guide rails, at least one carriage support cable reeved through said sheaves, one end of said carriage support cable being secured to the elevator car and the other end being secured to the elevator shaft at a point intermediate the top and the bottom of the shaft, and control cable guide means secured to the carriage, the lower end of the freely hanging loop of said traveling control cable extending essentially without restraint through and being loosely confined by said cable guide means.

2. Apparatus according to claim 1 in which a single carriage support cable extends around two carriage support sheaves, each sheave being rotatably mounted on the carriage adjacent the vertical guide rails of the shaft.

3. The apparatus according to claim 1 in which a first carriage support cablefextends around one carriage support sheave rotatably m ounted on the carriage adjacent one vertical guide rail and a second carriage support cable extends around a second carriage support sheave rotatably mounted on the carriage adjacent the second vertical guide rail of the elevator shaft.

4. The apparatus according to claim 3 in which one carriage support sheave is rotatably mounted on one side and the second carriage support sheave is rotatably mounted on the opposite side of the carriage.

5. The apparatus according to claim 1 in which the control cable guide means comprises a plurality of pairs of cable guide rollers mounted on said carriage, said pairs of cable guide rollers being disposed at spaced intervals in an arcuate path that essentially conforms to and coincides with the natural loop at the bottom of the traveling control cable, the cable guide rollers of each pair of said rollers each being journaled for rotation about a horizontal axis and being spaced apart a distance sufficient to permit the natural loop at the bottom of the freely hanging control. cable to pass essentially without restraint between said pair of rollers.

6. The apparatus according to claim 1 in which the control cable guide means comprises a pair of cable guide sheaves each mounted for rotation about a horizontal axis on the carriage, the loop at the lower end of the traveling control cable extending past the cable guide sheaves in light contact with the outboard edges thereof and extending freely between said cable guide sheaves below said sheaves.

References Cited UNITED STATES PATENTS HARVEY c. HORNS'BY, Primary Examiner ujs. c1. xn. 1s7 2, 0, 9s 

